add update script

update.sh

@@ -0,0 +1,13 @@
+# pull changes from git
+git fetch && git pull
+
+# update node deps
+npm install
+
+# migrate database
+npx --yes prisma migrate deploy
+npx --yes prisma generate
+
+# restart services
+service meshtastic-map restart
+service meshtastic-map-mqtt restart